maryland's question 4 asks voters to approve a law allowing undocumented immigrants to pay instate or incounty tuition at maryland colleges. passage would open doors for thousands of imgrants. >> i had cancer back in 2009. >> reporter: the stakes are hi for ricardo. he dreams of becoming an oncologist, but says he will never made it to medical school without the referendum. >> i'm a cancer survivor. my life was saved in johns hopkins by a doctor who is an immigrant. i just want to keep saving lives the same way my life was saved once. and i think it's really important to allow me, and allow kids to fulfill our dreams. >> reporter: but the maryland referendum is not the only critical question. >> let's be clear, this is not amnesty. this is not immunity. >> reporter: president obama's executive decision allows illegal immigrants who qualify to stay in the u.s. for two years without fear. mitt romney says he will uphold the same policy if elected. but it costs $465 to apply for the deferred action program. many immigrants who meet the requirement are afraid to take action until after th